• Energy Research

The level of urbanization is a key factor in urban development. In this study, to better characterize the level of urbanization, the panel entropy weight method is used to weight the factors of population, industry, and area to construct a composite indicator of urbanization. A panel regression between this composite index and the average night light values after fusion shows a strong correlation. An accuracy test indicates that the estimated value of fused average light as calculated by the urbanization level estimation model that adequately represents the urbanization level. On this basis, night light data is corrected for zero error on the pixel scale, and spatiotemporal evolution analyses are performed on the city and county scales. The standard deviation ellipse method is used to find that the spatial distribution pattern of the Beijing-Tianjin-Hebei urbanization level from 1995 to 2018 radiates and spreads to the northeast, with Beijing-Tianjin as the center. The spatial pattern shows a contracting trend that is strengthening year by year. Slope analyses show that areas with rapid urbanization growth are mainly concentrated in Beijing and Tianjin. The urbanization development speed of most counties in the Hebei Province is at a low level.

As absolute poverty in China, measured by the current standard, is being eliminated, the focus of future poverty reduction projects will necessarily shift to addressing relative poverty. Contiguous poverty areas have been identified in Hebei province around Beijing and Tianjin (HABT), and this is not conducive to the coordinated development of the Beijing-Tianjin-Hebei region. The dynamic identification of relative poverty at the county level within the region must be the basis for formulating scientific strategies for poverty reduction. Night light (NTL) data can reveal socio-economic information and reflect human activities, and has a wide range of other applications for evaluating and identifying poverty. For this reason, NPP/VIIRS (Visible Infrared Imaging Radiometer Suite equipped on the Suomi National Polar orbiting Partnership satellite) NTL data from 2012 to 2020 were corrected, and NTL data for HABT were obtained. A multidimensional relative poverty index (MRPI) that assesses being “free from worries over food and clothing and having access to compulsory education, basic medical services, and safe housing” using social statistical data was created with the analytic hierarchy process and entropy weight method. A panel regression model with fixed effects was established for MRPI and corrected NPP/VIIRS NTL data. The R2 of fitting was 0.6578 and confirmed a strong correlation between MRPI and corrected NPP/VIIRS NTL data. Based on this, the MRPI estimation model was constructed based on the MRPI and corrected NPP/VIIRS NTL data, and passed the accuracy test. Finally, using the national list of poverty counties, it was verified that, at the county scale, the corrected NPP/VIIRS NTL data could effectively identify areas of relative poverty. This study lays the foundation for the use of NPP/VIIRS NTL data in the identification of areas of relative poverty. It provides a feasible method and data reference for analyzing relative poverty at a smaller scale. The dynamic identification of areas of relative poverty can also provide a basis for formulating scientific poverty reduction strategies.

Abstract China's socioeconomic development, including urbanization, is now facing a key challenge of reducing carbon emissions. This study analyzes the driving factors of freight transport carbon emissions and the effects of urbanization on freight transport carbon emissions in China. The spatial durbin model (SDM)-stochastic impacts by regression on population, affluence, and technology (STIRPAT) model and geographically weighted regression model (GWR)-STIRPAT model are constructed to analyze the common characteristics and regional disparity of the above effects in China. The results show that: (1) The total amount of freight carbon emissions in China has increased from 3.7352 Mt in 1988 to 96.4158 Mt in 2016. Road freight is the largest increasing sub-sector of carbon emissions in the freight transport sector. (2) Urbanization level has a positive impact on road and aviation transport carbon emissions and has a significant negative impact on railway and waterway transport carbon emissions in some provinces, but has a positive impact on their neighboring provinces. There is a significant regional disparity in multi-freight transport carbon emissions. (3) The carbon emissions of freight transport have a characteristic of “path dependence”. The population size and energy intensity have a significant impact on freight carbon emissions. Different from waterway freight, there is an inverted U-shape relationship between the carbon emissions of railway, road, aviation freight and per capita GDP. We provide policy implications based on the findings, which is expected to contribute to the carbon emissions reduction in China's transportation industry.

The integrated night light (NTL) datasets were used to represent the economic development level, and visual analysis was carried out on the evolution characteristics of the economic spatial pattern of various urban agglomerations in the Yellow River Basin (YRB), at a county-scale, in 1992, 2005, and 2018. The Global Moran’s I and the local Getis-Ord G methods were used to explore the overall spatial correlation and local cold–hot spot of economic development levels, respectively. The spatial heterogeneity of the influence of relevant factors on the economic development level at the municipal scale was analyzed by using the multi-scale geographically weighted regression (MGWR) model. The results show that the county-level economic spatial pattern of urban agglomeration in the YRB has an obvious “pyramid” characteristic. The hot spots are concentrated in the hinterland of the Guanzhong Plain, the Central Plains, and the Shandong Peninsula urban agglomeration. The cold spots are concentrated in the junction of urban agglomerations, and the characteristics of “cold in the west and hot in the east” are obvious. Labor input and import and exporthave a positive impact on the economic development level for each urban agglomeration, government force has a negative impact, and education shows both positive and negative polarization on economic development.